How does a transformer oil BDV test kit work?

A BDV kit applies a controlled AC voltage across two standardized electrodes immersed in the oil sample. Voltage is ramped until breakdown occurs, and the breakdown voltage is recorded, usually with multiple repeated shots to get an average. The method controls electrode gap, rise rate, and stirring conditions to reduce randomness. IEC 60156 is a widely referenced method for the breakdown voltage test approach.